Apparatus for measuring unfrozen moisture in snow

ABSTRACT

A portable device is provided for determining the quality of man-made snow as represented by the amount of unfrozen moisture contained therein. The device embodies a flat plastic member adapted to be placed in contact with the surface of the snow and having two spaced electrical contacts exposed therein for engagement with the snow. An instrument such as a milliammeter is electrically connected to said contacts and calibrated to read in terms of the moisture content of the snow engaged by said member.

United States Patent 1 [111 3,757,212

Johnson 1 Sept. 4, 1973 [54] APPARATUS FOR MEASURING UNFROZEN 2,582,6291/1952 Hilton 324/65 P MOISTURE IN SNOW 3,487,302 12/1969 Griffeth etal. 324/65 R [76] Inventor: Frank Johnson, RD. 5, Princeton,

08540 Primary Examiner-Stanley T. Krawczewlcz Att0rneyAlbert Sperry eta1.

[22] Filed: Dec. 1, 1971 Appl. No.: 203,746

[52] US. Cl 324/65 R [51] Int. Cl G011 27/02 [58] Field of Search 324/65R, 65 P [56] References Cited UNITED STATES PATENTS 3,412,326 11/1968Jones et a1. 324/65 R 3,223,609 12/1965 Reeds, Jr. 324/65 R X 2,424,7357/1947 Boothroyd 324/65 R X 2,735,907 2/1956 lnman 324/65 R X 3,139,0856/1964 Custance et a1. 324/65 X [57] ABSTRACT A portable device isprovided for determining the quality of man-made snow as represented bythe amount of unfrozen moisture contained therein. The device embodies aflat plastic member adapted to be placed in contact with the surface ofthe snow and having two spaced electrical contacts exposed therein forengagement with the snow. An instrument such as a milliammeter iselectrically connected to said contacts and calibrated to read in termsof the moisture content of the snow engaged by said member.

6 Claims, 3 Drawing Figures PAramznsv 3.157. 212

\ INVENTOR I 30 34 Flam K JaHA/OA/ ATTORNEYS APPARATUS FOR MEASURINGUNFROZEN MOISTURE IN SNOW FIELD OF INVENTION In the manufacture of snowfor deposit on ski slopes, toboggan slides and elsewhere it is importantto assure the desired quality of snow to present a suitable surface foruse. Thus in applying snow to a slope for use in skiing it is desirablefor at least the surface layer thereof to be in the form ofsubstantially dry snow or powder. However, the condition or quality ofthe snow produced by a snow making machine may vary widely dependingupon the atmospherical conditions, the temperature, pressure andproportions of the air and water discharged from the gun or nozzle ofthe snow making machine and other variable factors. It is thereforpractically impossible to establish and maintain uniform conditions ofcoperation which will assure the production of snow which will have apredetermined quality as it settles on the ground or surface on which itis deposited.

As a practical matter and in the interest of economy, it is usual tosupply the snow making gun with as much water as possible in order toproduce as much snow as possible in a given length of time. On the otherhand it has been determined that as little as 5 percent excess water inthe mixture of water and air being discharged from a snow making gun mayproduce an icy patch of extended area whereas if as much as 30 percentexcess water is used the whole area on which the snow is deposited maydevelop into boiler plate," rendering it extremely hazardous orimpossible to use in skiing.

In order to overcome this situation and assure the necessary control ofthe snow making equipment, frequent adjustments of the equipment arerequired. Nevertheless, it is necessary to wait until the snow producedhas actually settle on a slope or trail and accumulated to a depth of asixteenth of an inch or more before the actual character of the snowbeing produced can be determined. The method most generally used intesting the snow heretofore is to gather up a handful of snow and tosqueeze it to see how it packs. If the snow is too sticky or packy theamount of water being supplied to the snow making gun is reduced. If thesnow is very dry the amount of water supplied may be in creased toassure the production of the maximum amount of snow while maintaining adesired quality. However, such prior methods of testing are very erraticand call for considerable experience on the part of the person testingthe snow. Furthermore, this manner of testing the snow produced does notenable the operator to know just how much more or less water should besupplied to the snow making equipment.

In order to overcome these difficulties and uncertainties in theoperation of snow making machines the present invention provides aportable device which may be carried from place to place and applied tothe snow to provide an accurate indication of the amount of unfrozenmoisture contained in the snow at any point. The operator of theequipment then can make the necessary adjustments in the supply of waterand air to any one or more guns in a system as needed to produce thedesired quality of snow in any area. Moreover, the amount and nature ofthe adjustment required can be determined rapidly and with a muchgreater degree of accuracy than has been possible heretofore.

For this purpose the device of the present invention is provided with asensing element presenting a flat surface formed of plastic or otherelectrical insulating material having spaced electrical contacts exposedtherein. These contacts preferably extend throughout the major portionof the exposed surface of the sensing element whereby they will affordan accurate measurement of the amount of unfozen moisture contained inthe snow to which it is applied. A battery or other source ofelectricity is connected to the electrical contacts and an indicatinginstrument, such as a microammeter, is connected into a circuitincluding the battery and contacts to indicate the amount of currentpassing between the contacts and through the snow. The instrument may becalibrated to afford a direct indication of the amount of moisture inthe snow whereby the snow making equipment may be quickly and accuratelyadjusted to increase or decrease the amount of water being supplied tothe snow making equipment, if that should be necessary to produce thedesired quality of snow.

Since the operation of snow making machines is frequently carried on atnight, the instrument further may be provided with a light for theillumination thereof to facilitate reading thereof.

THE DRAWING FIG. 1 is a perspective view illustrating a typicalembodiment of the present invention;

FIG. 2 is a sectional view of the sensing element of the deviceillustrated in FIG. 1; and

FIG. 3 is a wiring diagram of a typical circuit which may be employed inthe device of FIGS. 1 and 2.

PREFERRED EMBODIMENT In that form of the invention chosen for purposesof illustration in the drawing the device is housed within a casing 2which may be formed of plastic insulating material for the like andpreferably is impervious to water and moisture. An instrument such as amicroammeter 4 is enclosed within the casing and visible through awindow 6 to permit direct and easy reading of the instrument. The dial 8of the instrument is preferably calibrated and graduated to indicate thepercentage of moisture in the snow to be tested. Further, since snowmaking operations are frequently carried on at night a light 10 isgenerally mounted in the casing 2 adjacent the dial 8 so as toilluminate the dial for easy reading of the instrument at all times.

A moisture sensing element 12 is connected to the instrument 4 by meansof flexible conductors 14 which may be of any suitable length to permitthe sensing element to be placed in contact with the snow to be testedand the instrument read conveniently by the person making the test or bya person controlling the operation of the snow making equipment. Thus,if desired, the instrument 4 may be located adjacent the gun used toproduce the snow whereas the sensing element may be moved about fromplace to place in the area wherein snow is being deposited to test thequality of the snow at several points. In this way it is possible toassure accurate determination of the amount of unfrozen moisture presentin the snow and the nature and amount of any adjustments in the watersupply required to maintain the desired amount and quality of the snowbeing produced.

The sensing element 12 is preferably formed of electrically insulatingmaterial which is impervious to water and moisture. It is particularlydesirable to form the body 16 of the sensing device of a material whichis water repellant, such as Teflon, so that it will rapidly shed anydrops of water which may collect thereon and be capable of being wipedeasily to keep the lower snow-contacting surface 18 of the sensingelement dry.

The snow contacting surface 18 of the sensing element is preferably flatand has electrical contacts 20 and 22 exposed therein. These contacts asshown in FIG. 1 may consist of multiple strips 24 and 26 formed of metaland located closely adjacent to each other while being electricallyinsulated from each other by the material forming the body 16 of thesensing element. The strips 24 of the contact 20 extend in parallelspaced relation from a connector 28, whereas the strips 26 of thecontact 22 are similarly attached or formed integral with a connector30. One of the conductors 14, such as the line 32, is attached to theconnection 28 while the other conductor 34 is attached to the connector30.

The contacts or metal strips 24 and 26 are preferably embedded in thematerial forming the body 16 of the sensing element and are exposed inthe snow contacting surface 18 of the body or may project a slightdistance therefrom. The conductors or lines 32 and 34 may pass through afitting 36 carried by the body 16 of the sensing element and providedwith an O-ring 38 which is held in place and in sealing engagement withthe fitting 36 by the plug 40.

When the snow-contacting surface 18 of the sensing element is placed incontact with the snow to be tested and the contacts 24 and 26 areconnected into an electrical circuit, current will pass from contact 20to contact 22 through the snow. The amount of such current will beproportional to the amount of the unfrozen moisture in the snow and willthen serve to actuate the microammeter or instrument 4 to permit directreading of the moisture content of the snow.

The placing of the metal strips 24 and 26 is preferably such that thestrips are spaced one-sixteenth inch apart and will occupy a substantialarea of the snowcontacting surface of the sensing element whereby theamount of current passing between the contacts will represent an averageof the unfrozen moisture content of the snow engaged thereby and willnot be unduly influenced by the presence of an individual drop of waterwhich may be present in or on the snow being tested. Moreover bypressing the sensing element against the snow at several differentpoints in a given area any deviations in the moisture contact of thesnow can be averaged out to afford an extremely accurate measurement ofthe amount of unfrozen moisture therein. In actual practice, as littleas 1 percent of excess moisture present in the snow being produced canbe readily determined whereby the necessary adjustments in the snowmaking equipment may be made to assure the production of the maximumamount of snow of a desired quality at all times.

The electrical circuit employed for indicating the amount of unfrozenmosisture in the snow may be varied considerably. However, one circuitarrangement which has been utilized effectively is shown in FIG. 3. Asthere indicated, current for actuating the device is supplied from asource 42, such as a mercury battery, one side of which is connected tothe microammeter 4 through the conductor 44 which is connected to thecontact 20 in sensing element 12 by conductor 32. The contact 22 isconnected to the other side of the battery 42 through conductor 34,switch 46, variable resistor 48 and fixed resistor 50 in line 52. Anormally open switch 54 is connected between the lines 32 and 52 toclose a circuit through the ammeter for adjustment of the ammeter tofull scale by means of variable resistor 48 prior to use of the testingdevice.

When the device is to be used to determine the amount of unfrozenmoisture in the snow, the sensing device 12 is pressed against thesurface of the snow as shown in FIG. 2 with the snow-contacting surface18 and the exposed contacts 20 and 22 of the sensing device in firmengagement with the snow. Upon closing of the switch 46 current will becaused to flow through the snow from the strips 24 of contact 20 to thestrips 26 of contact 22 so as to actuate the instrument 4. The amount ofsuch current will depend upon the amount of unfrozen moisture in thesnow and therefore the pointer or indicator 56 of the microammeter orinstrument 4 will move over the dial 8 to indicate the amount or percentof unfrozen moisture in the snow. In this way the quality of the snowpreviously produced can be numerically evaluated and the need toincrease or decrease the supply of water to the snow making equipmentand the amount of any change required to produce snow of a desiredquality can be instantly and directly determined.

Since the making and testing of snow is frequently carried on at nightthe device of the present invention may be provided with a light 10energized by a battery 56 through lines 58 and 60. A switch 62 isincluded in line 58 to prepare the light circuit for use and thelighting circuit is closed upon operation of the double pole switch 46when actuated in testing the snow. The light 10 then need only beutilized when necessary and when carrying out a snow testing operation.

The construction thus provided is easily portable so that it may bemoved about from place to place to obtain several indications of theunfrozen moisture content of the snow. As a result, any error whichmight result from placement of the sensing element upon an isolated spotwhich is wet or contains an excessive amount of moisture can beeliminated by placing the sensing element on several other spots orareas representing usual average moisture containing snow. Further, byforming the body of the sensing element of Teflon on other materialwhich tends to shed or repel moisture the snow-contacting surface of thesensing element can be readily wiped dry and the danger of carryingmoisture from point to point on the sensing element itself iseliminated.

While the particular embodiment of the invention shown in the drawingand described above has proven very successful in use, the form,construction and circuitry employed therein are capable of numerouschanges and modifications. In view thereof it should be understood thatthe invention as herein shown and described is intended to beillustrative only and is not intended to limit the scope of thefollowing claims.

I claim:

1. A portable device for use in determining the quality of machine madesnow comprising an element presenting a substantially flat surfaceadapted to be placed in contact with the snow to be tested, said elementhaving a plurality of spaced electrical contacts exposed in said surfaceand electrically insulated one from the other, a casing having anelectrical instrument and a source of electrical current therein,flexible electrical conductors connected to the electrical contacts insaid element and to the electrical instrument and source of current insaid casing to permit said element to be moved about and placed incontact with the snow to be tested while the casing is carried in thehand or otherwise supported, said electrical instrument being responsiveto the amount of unfrozen moisture contained in the snow aginst whichthe flat surface of said element is pressed and being calibrated toindicate the moisture content of the snow thus contacted by said elementand electrical cntacts.

2. A device as defined in claim 1 wherein said element has an exposedsurface for contact with the snow which is formed of plastic material inwhich said electrical contacts are embedded so as to be substantiallyflush with said surface.

3. A device as defined in claim 2 wherein said plastic material isTeflon.

4. A device as defined in claim 1 wherein said contacts are in the formof a plurality of substantially parallel electrically conducting stripsof material occupying the major portion of the snow-contacting surfaceof said element.

5. A device as defined in claim 1 wherein a battery is mounted in saiddevice and a normally open switch is interposed between said instrumentand contacts for manual closure to actuate said instrument.

6. A device as defined in claim 1 which includes a light forilluminating said instrument upon closure of said switch.

1. A portable device for use in determining the quality of machine madesnow comprising an element presenting a substantially flat surfaceadapted to be placed in contact with the snow to be tested, said elementhaving a plurality of spaced electrical contacts exposed in said surfaceand electrically insulated one from the other, a casing having anelectrical instrument and a source of electrical current therein,flexible electrical conductors connected to the electrical contacts insaid element and to the electrical instrument and source of current insaid casing to permit said element to be moved about and placed incontact with the snow to be tested while the casing is carried in thehand or otherwise supported, said electrical instrument being responsiveto the amount of unfrozen moisture contained in the snow aginst whichthe flat surface of said element is pressed and being calibrated toindicate the moisture content of the snow thus contacted by said elementand electrical cntacts.
 2. A device as defined in claim 1 wherein saidelement has an exposed surface for contact with the snow which is formedof plastic material in which said electrical contacts are embedded so asto be substantially flush with said surface.
 3. A device as defined inclaim 2 wherein said plastic material is ''''Teflon.''''
 4. A device asdefined in claim 1 wherein said contacts are in the form of a pluralityof substantially parallel electrically conducting strips of materialoccupying the major portion of the snow-contacting surface of saidelement.
 5. A device as defined in claim 1 wherein a battery is mountedin said device and a normally open switch is interposEd between saidinstrument and contacts for manual closure to actuate said instrument.6. A device as defined in claim 1 which includes a light forilluminating said instrument upon closure of said switch.